A178787 Number of numbers <= n having distinct digits in their decimal representation, cf. A010784.

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 61, 62, 63, 64, 65, 66

Offset: 0

Author

Reinhard Zumkeller, Jun 30 2010

Keywords

• base
• nonn

Comments

a(m)<=a(n) for m=9876543210;

a(A010784(n)) = n; a(A109303(n)) = a(A109303(n)-1);

partial sums of A178788.

Examples

			a(12) = #{0,1,2,3,4,5,6,7,8,9,10,12} = 12;
a(24) = a(12) + #{13,14,15,16,17,18,19,20,21,23,24} = 23.
		

Links

• R. Zumkeller, Table of n, a(n) for n = 0..25000
• Eric Weisstein's World of Mathematics, Digit

Programs

Haskell

a178787 n = a178787_list !! n
a178787_list = scanl1 (+) a178788_list
-- Reinhard Zumkeller, Mar 15 2014

Mathematica

f[n_] := Length[ Select[ Range[0, n], Max[ DigitCount[#]] == 1 &]]; Array[f, 70, 0] (* Robert G. Wilson v, Dec 13 2016 after Harvey P. Dale in A010784 *)